[Delivery of epididymis-specific mRNAs from mouse epididymosomes into N2a and TM4 cells].

OBJECTIVE: To investigate whether mouse epididymis-specific mRNAs Adam7 and Crisp1 can be delivered into N2a and TM4 cells, and to provide an experimental basis for exploring the function of epididymal mRNAs. METHODS: Using RT-PCR, we detected the presence of epididymis-specific genes (Adam7, Crisp1, Defb22, Wfdc2, and Wfdc9) in the testis, epididymis, epididymosome and sperm of adult male BALB/c mice as well as in the human testis, seminal vesicles and sperm. We isolated epididymosomes of BALB/c mice by low-speed centrifugation, filtration and ultracentrifugation, fluorescently labeled them by PKH26, co-incubated them for 1 hour with the N2a and TM4 cells after 24 hours of starvation culture, and observed whether they were fused with the N2a and TM4 cells and ingested using the epididymosomes without PKH26 labeling, PKH26 dye without epididymosomes, and non- epididymosome or -PKH26 dye as controls. Then we detected the epididymis-specific genes in the N2a and TM4 cells after 1-hour co-incubation by RT-PCR. RESULTS: Adam7 and Crisp1 were present in the mouse epididymis, epididymosomes and sperm, and in the human seminal vesicles and sperm as well, but not in the testes of either the mice or men. PKH26 and Hoechst33258 fluorescence double-labeling showed that the mouse epididymosomes were fused with the N2a and TM4 cells and ingested; RT-PCR revealed the mRNAs of Adam7 and Crisp1 in the N2a and TM4 cells after 1-hour co-incubation; and Western blot exhibited the CRISP1 protein in the N2a and TM4 cells incubated with epididymosomes. CONCLUSION: Epididymosomes can deliver epididymis-specific mRNAs Adam7 and Crisp1 into N2a and TM4 cells, where Crisp1 may be translated into proteins, though their function and significance need to be further studied.

Novel compound heterozygous mutations in DNAH1 cause primary infertility in Han Chinese males with multiple morphological abnormalities of the sperm flagella.

This study aimed to identify genetic causes responsible for multiple morphological abnormalities of the sperm flagella (MMAF) in the Han Chinese population. Three primary infertile males with completely immobile sperm and MMAF were enrolled. Whole-exome sequencing and Sanger sequencing were performed to identify disease-causing genes. Subsequently, morphological and ultrastructural analyses of sperm flagella were investigated. The probable impact of genetic variants on protein function was analyzed by online bioinformatic tools and immunofluorescence assay. Three patients with dynein axonemal heavy chain 1 (DNAH1) gene compound heterozygous variations were identified. DNAH1 c.7435C>T, p.R2479X and c.10757T>C, p.F3586S were identified in the patient from Family 1, c.11726_11727delCT, p.P3909fs and c.12154delC, p.L4052fs were found in the patient from Family 2, and c.10627-3C>G and c.11726_11727delCT, p.P3909fs existed in the patient from Family 3. Four of these variations have not been reported, and all the mutations showed pathogenicity by functional effect predictions. The absence of the center pair and disorganization of the fibrous sheath were present in sperm flagella at the ultrastructural level. Moreover, the expression of DNAH1 was absent in spermatozoa from the participants, validating the pathogenicity of the variants. All three couples have undergone intracytoplasmic sperm injection (ICSI), and two couples of them became pregnant after the treatment. In conclusion, the newly identified DNAH1 mutations can expand the mutational and phenotypic spectrum of MMAF genes and provide a theoretical basis for genetic diagnosis in MMAF patients. It is recommended to conduct genetic screening in male infertility patients with MMAF and provide rational genetic counseling, and ICSI might be an optimal strategy to help with fertilization and conception for patients with DNAH1 mutations.

Effects of mutant huntingtin on mGluR5-mediated dual signaling pathways: implications for therapeutic interventions.

Glutamate excitotoxicity is thought to play an important role in Huntington's disease (HD), which is caused by a polyglutamine expansion in the HD protein huntingtin (htt). Overactivation of group I metabotropic glutamate receptors (mGluRs), which include mGluR1 as well as mGluR5 and are coupled via phospholipase C to the inositol phosphate pathway, is found to be involved in mutant htt-mediated neurotoxicity. However, activation of mGluR5 also leads to neuronal protection. Here, we report that mutant htt can activate both mGluR5-mediated ERK and JNK signaling pathways. While increased JNK signaling causes cell death, activation of ERK signaling pathway is protective against cell death. Expression of mutant htt in cultured cells causes greater activation of JNK than ERK. These findings suggest that selective inhibition of the JNK signaling pathway may offer an effective therapeutic approach for reducing htt-mediated excitotoxicity.